The vast majority of us follow the common-sense rules of summer dressing. Not too short, tight, baggy or revealing — most especially not any of those at work.

The workplace, in fact, is an area where a lot of otherwise smart people go terribly wrong when the temperatures climb.

"The best rule of thumb is, if you're not sure, it's better to be too formal than too casual," advises Fran Liontakis, regional vice president of OfficeTeam, a division of the temp placement firm Robert Half International.

Top no-no's, she says, are sheer clothing, flip-flops, crop tops and low-rise pants.

"You should always dress to the position you aspire to," says Liontakis, who cites an OfficeTeam survey of 659 companies that found only 1 in 4 had a relaxed summertime dress code — even though employees often dress like there is one.

Some of the major sins of summer, at least when it comes to clothing, could be avoided by checking a full-length mirror, front and back, before appearing in public.